1. Field of the Invention
The present invention relates to an image heating apparatus configured to heat a toner image on a sheet. The image heating apparatus may be used, for example, in an image forming apparatus such as a copying machine, a printer, a facsimile machine, and a multifunction peripheral having a plurality of functions of those apparatuses.
2. Description of the Related Art
Conventionally, there has been proposed a fixing apparatus (image heating apparatus) configured to fix a toner image formed on a sheet by using a heating belt (endless belt).
In the fixing apparatus, repetitive bending of the heating belt may cause a fatigue failure of the heating belt, or some accident may cause a breakage of a lateral end portion of the heating belt (partial breakage may occur from the lateral end portion to a lateral inner side of the heating belt). In case such a breakage occurs in the heating belt, the breakage needs to be immediately detected.
In view of such circumstances, Japanese Patent Application Laid-Open No. 2011-33832 discloses a belt position detecting device for belt lateral movement control, which is provided at one lateral end of the heating belt and configured to detect a breakage on the one lateral end of the heating belt. Furthermore, a breakage on the other lateral end of the heading belt is detected by using the belt position detecting device. To this end, a link mechanism extending from the one lateral end to the other lateral end of the heating belt is provided on the side of the outer surface of the heating belt.
With this, in the image heating apparatus described in Japanese Patent Application Laid-Open No. 2011-33832, the breakages of the heating belt can be properly detected.
However, in an apparatus structure in which a large installation space cannot be secured on the side of the outer surface of the heating belt, it is difficult to employ the belt breakage detecting mechanism described in Japanese Patent Application Laid-Open No. 2011-33832.